Shutter



2 SHEETSSHEET 1 G. B. RICHMOND SHUTTER 1 NQV /Q w a INVENTOR. 660 06 B Hcwmava Wm \M: v mm W I l N 9 July 22; 1952 Filed 001;. so. 1946 G. B. RICHMOND Jul 22, 1952 SHUTTER 2 SHEETS-SHEET 2 Filed Oct. 30, 1946 o o wm 1N VEN TOR. GEORGE E. lP/CHMO/YD ATTORNEY Patented July 22, 1952 A c -UNITED STATES PATENT ;OFF ICE Y SHUTTER H I I George B. Richmond, Memphis; Tenn, assignor "-to'v Hunter Fan and Ventilating Company, Inc., 4 Memphis Tenn a corporation of New Yorln Application October so, 1946, Serial No; 706,731

' Thisinvention relates to-iinprovenie'nts in shutters that are used with exhaust fans. Moreparticularly this invention relates to improvements inhorizontally disposed shutters which are used with certain kinds of-exhaust fans that are to be operated in the attics of houses or buildings .y Y 12 Claims. (Cl. 98-416) andare, because of their location, commonly calledattic'fans. 1 I "It'i's, therefore, an objectof the present-invention to provide an improved horizontally-disposed shutter g-that canbe used with atticians. Attic exhaust fans, to be of value in properly ventilatinga, house or building, musthave comparatively-large ceiling intake openingsf those openings must 'be provided with closures topre- YQILF ve ccssive' ,l oss j of heat from the house or building during the winter season. The two 010- sures that are most commonly used in connection with attic fans are 1) trapdoorsthat are opened in the springof the year and are closed in the fall, and (2) self-operating ceiling shutters that will open to permit escape of air during the "on periods; ofgthe fans and will automatically close toprevententrance of dustfhea-t or other objec tio'nablef' matter into the living 's-paces' of the house 'or building when'th fans are off. I he trapdoorsare workablefinthat they provide large, unimpeded openings through which air can 'be movedvvith little'resistance, but they are undesirable sin'ce they are usually open all season and permit thej'undesired entry of dirt and heat into the living spaces of the house or building. As a resultfthe. usejof trapdoors withattic fans is not completely satisfactory. The self -operating shuttersobviate some offthe difficulties-experienced with 7 the trapdoors, because those shutters will tendnto close whenever thefans are off. However, in viewof the'fact that the-draft of air produced by thefan is the motive force'to open theshutteri and view of the] fact that such a draft can exert only limited pressure, a deli cate counterbalancing i rnechanism" is necessary with the self-operating shutters to prevent serious reduction in the amount of air that'can pass through those shutters: [Springs or weights usually provide the necessa'ry counter-tension in the counterbalancingmechanism to offset the weight of the's'hutter bladesand the springs or weights also perinit so me" adjustment to be made to meet 'cliangingoperating conditions. While the automatic ceiling shutters are'more desirable than thetrap'doors as closures for attic fans, they are themselves objectionable because (1) the counterbalanci' ig-devices can be prevented from operatingproperly loy'gradu'al accumulations of grease or dirt onthe-movlng partsthereof-and; thedevices can thus-preventnormalopening or-closing of the shutter blades; (2) fires occurring in the house or building could, create air disturbances which might act upon the shutter andcause-it-to open, thus permitting smoke'or flames to spread to other parts of the structure, (3) the tendency.

offlthe shutter bladesto close can create suificient back pressure to. noticeably reduce the air capaci -i tyof newly'installed attic fans, and that tendencycan become more pronounced as the iangets di e ty with the passage of time; and (f1) the shutter blades are not-held positively in closed-position and thus back drafts inthe, attic can" cause l the shutter blades; to flutter and make disturbing noises when the fan is off. I

'Forthese various reasons; the closures-;- that are commonly used in connection with'attieem; haust fans are objectionable; '-I'he present invention obviates Jthese objections by providing a manually operated, horizontally-disposed :Geiling shutterthat is held openby'a control chain and is positivelyiclosed by a compression spring whenever'the control chain is released. .Moreover," the shutter of the'presentinvention emlcodiesdepende able, automatic fire-protectioni'eatures that oper: ate to closetheshutters and'stop the fan when: ever'a flame or: a mass of hot air reaches the proximityof the'shutter. :In additiomthegshutter ofthe presentinvention has a strong, horizontally-disposed frame that supports the shutter blades an'd'also 'supports a control bracketyvhlch is in the center of the frame and permits; the shutter blades toassume uniform angular -inclinations 'relative"to'the -axis of the fan; 'More over, the shutter of the present invention and its operating mechanism is protected againstinjury due "to accidental: contact with obstructions in the house orbuilding and vtheoperatingmechanism positively'biases all 'of the shutters-to closed position; 7 'It is, therefore; antob'ject 'of the. pres? ent invention to provide a'pluialityhf shutter blades for an attic'e'xhaust fan =and:an operating mechanism that permitsithe shutterblad'es to assume almostjjpe'rpendicular inclinations when the fan isoperatin'g and to positively-close, each of the shutter'blad'e's'when'the fan isnot operate tion'ed within the arcuate portions 266i the shutter-bladesll are generally arcuateinserts' 28' of moisture-resistant, resilient material which. will bearagainstj the cylindrical portions '21 of adjacentlshutixerv blades 24 and will cooperate with the. portions 21/00 keep dust; 'airandc moisture fitomvfiltering by the shutter blades ZQ'WhQIl those blades are fin. the closed position, jas; show'n' i' in Figilfl, In additionrv theinserts. 28 will av'oicl metabolic-metal. contact between the adjacent shuttfiliblades 24 and will thus eliminate noise in the operation ofv the shutter. f The four ?shut ter bla'd "s;24"tha't are immediately adjacent the Q'en-H tra ubve p te "5 ar fl rid dwwitl 1 eiitendins sides; .asiar h r t .qfit e es; Inst ad; th s i qu ,,i. hu te e, ene a ly itr p qidali c nfi enabl t emjt il'sa a ainst and v r a sfi 24. h f e -l d e of not'p br ic' l'p rt ons of a a nt s u te b d er i 1 t e si s @iith ems 15,5 a d h ff't fe'f. up ortinapl e 1 -1,. n 'flli the shutter blades 24 providea substantially airt'i" t'surfape for the frame when theyare closed. willbe noted that with the shutter shown in thedrawing, there are four distinct groups of shutter bladeslt; twofgroupsin the right hand 11 v oithe frame and two groups "in the "left, 11.? $1 half of he fra 3? i Q' i l i in each half are separated 'by thechannels "l| and thus a separate group ar -shutter blades 4 2 4" is provided in' each of-the'founquadrantsbf the frame. Each of'the shutter blades Z4,--with "the eizce'ption of the four shutter blades "immediately adja exit the central supporting --p1ate jf|s f the me; isproVided"with 'a' hinge member 29 tliutexthds upwardly adjamentthesides of thechannels ll that are disposed longitudinally off the framei- The hinge members ZBare rO- tatabli'attached-to connecting rods 30 which ex tend between and connect together the hinge members29 oranv 'oneparticular group ofshut; tei blades'l l, thus permitting 'all' of 'the shutter longitudinally "of theiframe and terminate; ad-l jacentv the" central supporting plate [6 of the" frame. .With this construction, movement of the;

constitutes a center bracket-for the frame; The;

center bracket 36 has a vertically-extending". slot upp orting plate 1'5. With thoseifour: r

blades that arti ular" group to move together at the same time "The 'fourshutter blades 2'4 which-' are most closely adjacent to the-central supporting plate I6 are equipped with :upstancling hingenmembers 3!; the four-"shutters that areziir'rimediately adjacent the fourshutters at i the 1 center of the frame are also 'provided with upstanding hinge members 3 I. The hinge members'3xl are connected together for conjoint movementby the connecting rods 32. -It' will'benoted that. the four shutter'blades 24 which are-"adjacent the fourinnermost shutter blades24 have hinge-members 29 as well as the hinge members 3|; as a result, those particular shutter blades will move in response to the -movernent. of'the sc m t rein 'teri fl tr' hea h o e Theexr. V ace ofthebra t 3 6 ism9Qt l' elfri mi e ,"f nin t dfltegi ati n' herea neni an inner hamster subs'tan? t el y bsfs 'aq et "136 1: t .T ei ollar s a v extending ,openingtherethrough, and that-fopen .elfri s' he'pi rfl h qh sss thr n r g sters with theslot fig' thebraclret itfflh e piln ddlimitsthe upward movement ofthe collar SZtand I it-may, if'desired, also serve to limit the downward movement of the; collar 42. Secured tothej central supporting "plate 1.6} but spaced horizontally; therefrom, is a ve'rtisally-disposed support .46 and that support carries a V-shaped rocker armf lfi Which-can oscillate relative to the support 46-. --The vertical support is so positioned relativeto-the bracket 36"that the'rocker arm 48 registers with and eng ges-thetm 44 I offtlie collar Hand therocker arm is set so the pin-'44 bears against the inner" surfacesof the f tlief rocker-"arm '48. A mercury switch 501s soured to and rotates-{with the rocker-arm 48, f and the-mercury switch 59 is connected by means fof conductors 49 to a socket "41; The socket {47- receives the "insulated conductors 53 from; an alternating current scJurce,-"notshown, and the socket 4l alsorec'eives' thefinsiilatedc positionI-the fair' motor iv'vill not be energized;

As? shown "in T the? drawing, the mercury switch 7 EB t/ilI- cause-the motor 'toi-be"en'ergizedwhen connecting rod 3!) and willcause a concomitant conjointmovement of the four innermost shutter blades-24-byreason of the connecting rods 32. ;As a-Vresult'of thisiconstruction, all of the shutter blades 24 can-open andclose at the same time.

Itshould be noted that all the-shutter bladeszd opens with theiriree edges toward-the center of Ithe .frame, thus providing uniform, ,turbu lamefree flow of. air'pastthe shutter blades 24. Leversr33 are connected to the hinge-members 29fof the four shutter blades 24 Whichare adjal cent thefour innermcst shutter blades 24,. and

those levers are connected to the ends. of-the crank. levers 34. The crank levers 34 inturn are rotatably secured to the channels] If. Connected to pointsintermediate thelengthsoi the-crank levers" 34 are "connecting rods 35 which extend the shuttersia're open; as they are in" Fig. 2 andi it will cau'se the" motor to be 'de-energized when .the "shutters are iclosed; as they are in Figs: :1; andr3'." The motor-and 'fan are secured to ajr 's'upponting frame', not shown," and that sup= portinga framewill rest ionsthe section 5,1 ofrubi ber hose that; isrjse'cured- ;tothe: support. 2 0 This sectionjt'lgwill absorb vi-bration iandinoiseand wfll lr a ke the installatio increefiicientand depm" 'w zt all i ontal'ly projecting an e-A a i h.. V tabe a eq edlath lever 15 1. 7 s? le v52 t 'rn'rotatablysecured by thecpiyottfia" to lyuextendingends ofthe connecting ,to the-hinged i-levers ,54 that are rottachedllto.thegplaite s. :NVithl such fihe1reciprocation=of the collar 42 knee -action on the r-le lverjsn 52., and; s4 (eciproca'tionj eatin L liar-1.. r p eviously indicated, this recipro he opposite walls thereof and thetwo e 9 2 .d am en f" h pass n -t eme eter, not shewn. Tl'1eplug'-"4l-is sowiredthat one of the massacre eeti eafii enei the cearle lls was 35. w lle e re .7 i are 34, and a c ee f are as enslelq ne 2f the shutter bl es The m emfnte he era .2 s. ulate by t1! e eie e ei e Q th sprin i hat $1 k cir les. heb eeket 36 and Dr s s, ain the underside 9 ll. qllfr 4,2 and thei 5.8 whiqll acts upon the pin' 44' through the medium or a the ma ly r s n iv kfii. Th S rin 55 ur h c ll r 42v nd t e wi eht in i sta heer n o e circuit P s i n. an to tart tlie ra m er and, to ne; the shu ierbled s '4) i s nee y to pu he cha n fitdQWQWtlrdie renk tbermellme nk 5e 7 will remain close d and h ldin them closed. This wiil elirr u e r at reaches the shutter male any ch m y ele t hrou h t e shu er. he h in 5 h t H h eo t permit ea y m alater 9t t e ch in an t e hair. 5% s h ld in the s ut r- @12 .Jeei n fairest-mat ng sitiea by i t a l t fit, 1,1 s eet s ol w ll? r ns eat sl ewa ind-1e bet r: r the br cke 1% 1 r f that arn qr ma es teeT e erlor di me i. the ra ket 36,. an h hi s -see e i h. he Q9 end 'o th Y ter a s ar o h Q ea e- W th s h at it p ssibl t hold h hai mere y y me as the cha n 1 29 t e o iqn-shqwn in F etw er n t the ra ed. secti s e the hain 58, wil 11 nto he sl t .6 nd w ll e h d ther b t e ha e. c en ent o 60 a the pressures ere b t pr n 55- r vemeat o h ch 8m n the c t of e l r opening with which the slot 52 is contiguous will ermit the chain to move. upwardly into circuit-V opening and shutter-closing position.

t wil e t d a is c struction pro: Y d sa sin po nt f applicat o 0t fo ce for both the shutter-opening mechanism and the mercury switch, namely,=the pin 44; This is a very important feature because it eliminates the necessity of precisely dimensioning a chain-that will simultaneously act upon a switch and the shutter-operating mechanism. Moreover;it eliminates. the possibility that one portion of 'thechain may break and permit the fan to. operate whilerthe shutter blades are closedyin addition, it facilitates the use of a single fusible-element in controlling the movement of the shutter blades and the actuation of the switch. With the construction of the present invention, it is possible to use a chain of almostany suitable length in operating the shutterpand there is 'no problem otf'preci'sely dimensioning that chain.

It should also be noted that the construction of the present invention permits the chain to hang down in the direction of movement of the collar 42. As a result, the chain does not have to be passed around pulleys, with consequent incr as s n frict n nd conse u nt ncr as s in th St se the hain- M r o e t wil s lo kin c t e chain in, sition by p r.-

the shutter blades 24 ar willbe. released and and the, resilient sealing inserts s r j i e h wn. n he dr y ies i e se high Y deslra lebe au t has the c er re k en ctine ro an opera space inwa ai ritm the edges or the tr thus, those em nts a e out r he wauo be ral elements of the house .io' ts and other stuct or buildng in which the shutter used. As a shutter can be fitted into places wh e,

ult th ether-shu t rs ca not e se a d the one at the-shutt r will ne iniure' r b 1 s st uctural em of t e use r it ate -o More e i i be i tt s tempest h llow and, s t los d a he toe?! m ll thus the ther flally esro isiv l nk d in the path of t. o lie-lin e ho air evbl'v d y, and will respond promptly t to. sex-lens lac o se in pera u ei h v n w-ef th lmt ee Moreoverjit. will be noted thatthe; free edges of v de ely l asa the pivoted edges of adjacent shutter blades 2} 28 wilikeen out,

dust, dirt, rain and other objectionable fmate-,

, rials.- Furthermore, it' willbe noted that the.

spring pressure is distributed over each of the shutter blades 24, and thus vno single shutter: blade has to absorbalarge pressure. In addition, the construction of the present invention permits the wires 49 to lie under; the various operating levers and thus keepsthem out of the way of the shutter blades 24. The construction additionally protects the wires 48 by reason of the longitudinally-extending chan, nels H which underlie and partially surre those wires. Thus hot blasts oi air or flames c not directly contact the wires and cannot b off or melt the insulation of those Wires. Itwill also be noted that whenever the collar 42 moves, and that collar will move at all times it is not positively held in shutter-opening and circuit; making position, the mercury switch 50 will be moved to circuit-opening position; The us ot the mercury switch 50 is highly advantageous circuit op'ening without arcing; in addition, in

the event of fire, there is but little possibility that the flame could contact the mercury switch 50 since the bracket 36 is spaced to one side of the mercury switch 50 and the mercury switch 'is slsiielded from the open slot 38 by the rocker arm Whereas a prefered embodiment of the present invention is shown and described in the drawing and accompanying description, it is obvious to those skilled in the art that various changes may be made in the form of the invention without affecting the scope thereof. b

WhatI claim is:

1. The combination of a frame, a pluralityof shutter blades rotatably secured to said framefa switch movable into on and oil positionfa lever pivoted to said framea rod extending be tween the free endof said leverand oneiof-said shutter blades a'second rod connectingth f "e ends of said shutter biade's 'togther, a recipro cable actuator, a connecting rod extending from? said actuator to a point on said lever whichis intermediate the ends of said lever, whereby a small movement of said actuator provides a large movement of said shutter blades, a link between said shutter blades and said switch whereby movement of said shutter blades is accompanied 'by movem'ent of said switch, resilient.meatisbi'ase ills sai q ator'to shutt losing pos t on, and

ting levers the j I manually operable means adapted to move said f-actuator, said resilient means preventing flutter-- Econnected to and-actuable by said reciprocable "member; a--lever that isconnected to said crank lever and to said knee action linkage and causes "movement-of said shutter blades whenever said "refc ziprocable member reciprocates, a switch movfa-ble'into on? :and of! position, a projection- .Z

mov ab'le' with said reciprocable element to actuate said switch-and resilien'tmeans biasing said 're'c'iprocable' -member; -to circuit-breaking and shutter-closing position, said reciprocable memplate, a hollow cylinder secured 'to and pro- :jec'tin'g upwardly. .fromv said plate;;; a slot in. the Wallg'of saidxcylinder i-that .is :Lparallel, to; theEaXis bf-saidcyIinder, .'a collar that telescopes; oversaid cylinder and is .reciproc'able relative to= said cylcinder, Caz-pin ,thatjris carried by; said collar and extends .ithrou'ghg'said slot ,into said; cylinder, ;1a iusibleilink connectible to said-pin, a chain connectibleto; said'ifusible link, .a plurality pf levers 1 between said, collar and said shutter blades, that open and close said shutterblades in response to movement-70f said collar, resilient means biasmgsaid-,c'o11ar;for;movement o shut e position; a rockerv arm rotatably positioned adjacerit said cylinder, and amercury switch carrie y sa met ame d mq i n oii i position, said rocker arm being operable by said pinicarridby:said'collar. 1i 1 T 'i' f6. rnagsnuaea ag rr m'e, a central uppor'ting plate'secured to said frame, a plurality'of "shutterblades spacedbutwardly fromjsaid 811pporting'plate, a'hollow cylinder secured to and projecting upwardly from said platef-a slot -in the wall of said cylinder which -is'parallel-te' the bar serving as a single point of application to which a single force can be'applied to cause simultaneousmovement of the shutter blades-and "actuationbf the switch.

' "3;-T h e; combination of shutter blades and an actuating;niechanism therefor that comprises a frame; a plurality of shutter blades rotatably secured to said frame, a stationary bracketsec'ured to and carried by said frame, a collar mov- -''able relative to-said stationary bracket, a spring biasing said collarfor movement toward one i endofjsaid stationary bracket, a switch respon sive to-the' position ofsaid collar to move to -o n or ofi position, manually operable means ftodetermine the-position of said collar relative -'f'to said bracket; and connectinglinks between said-collar-and said shutter blades to control the opening or closing of said shutter blades, said -bracket beingdisposed centrally of said frame, "said bracket being hollow and having both ends ----open" wherebyfiames can pass directly through, v

*s'iid bracketand contact a fusible link which is "positioned withinand movable relative to said "jbr'acketand is part of said manually operable means;

-- 4-. :1n shutter, a frame, acentral supporting plateisecured to said frame, a plurality of shutter blade's 'space'd outwardly from said supporting 'plate, -a hollow cylinder secured to and projecting upwardly from said plate'with its axis normal to said plate, a' slot in the wall of said cylinder that 'is-par allel'to the-axis of said cylinder, a collar 5? -=t'e'1escopes oversaid cylinder and is recipca ble 'relative to said cylinder, a pin that is ffcarifiedbysaid collar'and extends through said axis of-said cylinder} a collar that-telescopes over 'andis reciprocable relative to-jsaid' cylinder', a pinlthat Tis: carried by said collar andrextends through'said slot into said, cylinder,'g;a fusible nkrcqn qt bl t a dn .aehainon ectibl to, said usi in arlu amy ,o eve ros tioned between said collar, and said shutterblades that open and i close said "simme blades nfresponse to movement; for saidjcollan'fi'esiliefit means b as n s df o ar or mbv mentf oshutter-closing position, "a rocker arm rotatablypo- 'sitioned adjacent said cylinder, a mercury switch carried bysaid rocker-arm-and movable to on positiona'nd off position, said rocker arm being operable by said pin carried by-said--coll'a'r, and a switch that is adjacent to said collar-and is responsive to movementof said collar toenergi'z'e': and ode-energize a motor which actuates-a fan adjacent to said shutter, said resilientgmeans 7.;The combinationof a frame, a supportld is so ia i s; a 1ar. for; ovem 9 aus sa d- Sw t h e-j e i aid-m poses inwardlylof said rame; said support'bi'rig smaller than said .rrame and being adjacent, the

7 ,cente'rjof said'frame, a channel which is secured movable into:ffonflandjioffflposition,

outer ends-secured to said to said frame and to said support and "spanning the j distance between said frame and 'saidsupport, -plurality*of pivots' havi'n 'g their inner ends secured to 'said channel-and having their I V frame,--a-plurality"of shutter blades that are supported bysaidpivots, a switch that is: mounted onsaidsupportla'ndl'is amanually V opera eci r catin emen.t:, onfined; for. re-

ijslotintofsaidgcylinder, a fu'sible link connectible' v.tol saidpin, a. plurality offleversflpositioned beflt'ween'said collar'and said shutter blades that {been and close said shutter blades in response ftp movement of said collar, resilientmeans biasing; said collar for movement to shutter-closing ;,;-posi tion, anda manually operable element con- ;inelctedrto said-fusible link ,and' thus to said acollanisaid.lmanually operable element being omovablelito'move said collar to shutter-opening -er i e i a; inkag tha ext 11 ip qqat nsi mo ement. betwe l s e. .rnanually, operable reciprocating elemen and 7 said shutters to cause movemnt oflsaidff utter blades, a second,linkagefextendingj between aid manually operablreciprocating element arid "said switch, and leads estendingftoj saidiswitch said channel having upwardly extending "sides that aprotecti on-and cover for said leadsf'said =switch being carried-by'saidsupport and being tact'sai'dleads.

located inwardly 0f= said frame, said leads overlying and beingprotected by said-channel whereby blasts of flame or hot aircannot directly c'on- 218.:lIhetcombination of ai'rame, a plurality of shutter blades rotatablysecured'to saidf am i pivots an means to move saidshuttefrblades,

and-Joe":

said-means including eccentric hinge members wliich are securedto 'saidshutter blades at points spaced from said pivo'tsiand-which project out- -wardly from said shutter blades, a connecting -rod pivb'tally' secured to said eccentric hinge "members; a link piv'otal'lys'ecured to one end of saidjconnecting, d, a crank lever pivotally sesaid frame, a reciprocable member lfi vetirans e l 6f the f ib 5f si e- .tlonefrsaidoreci ro lc m m er, a lever cononectedtoisaidcrank lever intermediate the ends .ofzsaidcrank lever and is linked to said reciprocab1e member lby-said pivot and said linkage, -a"iir6jection mounted on said reciprocable memsaid projection being movable through a 'dt'erffiined path when said reciprocable memo es, a switch that is adja'cent thepath of n vementof saidprojectionandthat is movable into; ifon" r l foi position by Said projection actuationoi said'switchiscontrolled by 1p ion of said reciprocable member and th co c fi afii j iifini 9 sa e e n -.i ll si ifi e i ahs seeiired sa d re inm memberi idhcld ne mea eing selective y a d .,releasably,.engageab1e with said a fr m said resilient means biasing said reciprocable member to.circuit-breaking and shutter-closing position. Bahia shutter that is disposed adjacent a fan indh'as afraiii'e; piuraiity 0f Shutters rotatably secured to'said'i I ay connecting rod tosaid shiittrs to cause conjoint movet thereof, and a manually operated actuo emeni w i qm i fis ve ori'endthrof pivoted to said ra e ad- 51 e iij1 i de 's i l ii ti .rjOd, vsaid l nk .r spqn ne to a o of i a levr v al iciut.sai .frame.toinmle said ne tin r d and thusmovesaid shutters, and a-driving rod :thatis connected to said'actuator and to a pivot intermediate the ends of said lever, said driving rod being movable'to causemovement of said lever;- these'cur'ement of said driving rod t a 'the ends of saidieverand the a termediate iifis ca singsaidfr'ee end r, sa d link to move fa h hangsai driving rod move P r I p Y 1996 man ,seoi ai s na l test sa d .2 YQtsa n eQ na I'mk extendbfitw iis id, shutter blades anda point on so .llever ntermediate sa d points .on said lever, and

a movable element connected to said rod and is s (1 piv'jois. aliiik oizte'iijai ig b w' e iithe 5Q saids i supported b said tr m an aid nk; to the nee end r said of shiittrbIade's jsoiir to's'aid iiamo b V M lever, said point on said lever being spaced jiqmithewpointwhere saidlever is ,pivotally seaovatie, io'oius aov a i o saidfrodt i f tatabl e red said lever andthe eby ca se opening or of said shutter blades, thesecurement of said rod to said lever intermediate said pd f said lever enabling a predetermined movementlof s v .rqd a e a mer m n f. he r' s point onjsaid lever and a movement o'isaid shutter blades which are greater than thamov'ement of said movable element and said toda 1 1 hutter that c mpr ses a frarnaa plur 'iityof shutter blades that are rotatably secured to said frame, and means to provide movement of said shutter blades, said means including a eint q bl e ber. a e e hat ha b e. ridi t d c sai t m-san h st f r dli Mia t rodu pn edat V 2 end t said 'E conne e e t ot erl ndt tq 9f d hu -i9 blades, a link that engages said 'shutterbiades onn c em Pr. m em nt irijiiniso .J kneeactionlinkage which includes a plur ity oflevers that are connected together and that are aci abl b k ciprm b bon' ii tra versel o the re fi iprd fa ab said reciprocable element, and a connectin'g fqd pivotally securedto said lever and to said knee cni ci ne ro thus m n q t qnl 7. dis sai lat r mov men ih eidt elro ro a o Q sei 'Qn 'sh d im v men Qfsa link, animtat q o a d ot en hu b ades he ea emeht o s c nec n rod. iim e at lth .eiiqsq a l ve a terme e ePWQP -egnnectionbetween said lever and said frame andthe, connection between said lever and said tie if d providing a multiplication of movement or sa d tt rblad s- I s t erst a s, dispo sdua ia n f .e and a ame a plura t isnu fi s. m- .to aid am y ivo wenheqtine r se r to Said. l u te sm iis .Qsinim i mevemerit t re f and a anuallkpprat c a w ic as a a o m ementb predetermined length, the improvement which qqm isfis a h l su po t .f sai c u nect'ed to said actuator by said fusible link; the

lower endiof said hollow support being open to said one "side of said frame to permit flames or hot air tocontact and act upon said fusible link, said support. protecting said fusible link against breakage through contact with other elements .of

said shutter, said link being fusible to permit .mgvement of said actuator independently of said I chain.

(References on following page) than said paths or, movement 7 REFERENCES CITED Number Name Date The following references are of record in the 1,971,920 ROSS 1934 file of this patent: 2,077,175 Kornbau et a1 Apr. 13, 1937 2,225,885 Penman Dec. 24, 1940 UNITED STATES PATENTS 5 2,314,003 Mader Mar. 16, 1943 Number Name Date 2,323,178 Denman June 29, 1943 938,067 Maranville Oct. 26, 1909 2,337,863 Beeler Dec. 28, 1943 1,117,287 Warden Nov. 17, 1914 2,355,846 Willey Aug. 15, 1944 1,493,023 Coakley May 6, 1924 2,396,025 Seid 1 Mar. 5, 1946 1,601,100 Baker et a1 Sept. 28, 1926 10 2,407,284 Kennedy Sept. 10, 1946 1,627,194 Norberg May 3, 1927 1,663,199 Hirschman Mar. 20, 1923 FOREIGN PATENTS 1,788,556 Wood et a1. Jan. 13, 1931 Number Country Date 1,791,790 Burke Feb. 10, 1931 142,392 Germany July 9, 1903 

